Apparatus for washing machine including a drain-back groove

ABSTRACT

A washing machine including a perforated inner basket and an outer tub is disclosed. The outer tub includes one or more grooves on its inside wall to redirect extracted water from the perforated inner basket downwardly into a collection area for disposal. The groove may be generally vertical or angled along the upper portion of the inner wall of the tub. The groove preferably includes an undercut portion that extends in the same direction as the perforated basket spins.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to an apparatus for washing clothing and other items. More particularly, though not exclusively, the present invention relates to an apparatus for washing clothing that includes a drain-back groove to minimize excess sudsing during the removal of wash water.

[0003] 2. Problems in the Art

[0004] Currently, top loading washing machines typically include a perforated basket which holds the clothes or articles being washed and an agitator to mix the clothes and articles in the wash water. At the completion of the wash cycle, the perforated basket is rotated at a high RPM to extract the wash water from the perforated basket and the clothes and articles therein. Because of the spinning nature of the perforated basket, the extraction is known as the spin cycle.

[0005] During the spin cycle water flows out of the holes in the perforated basket and contacts an outer tub. Due to the speed of the perforated basket during the spin cycle, the evacuated water continues to flow in the direction of the spin even after contacting the wall of the outer tub. This delays the water's arrival at the base of the tub where it is eventually pumped away.

[0006] Often, the evacuated wash water lingers in the upper portions of the tub, eventually accumulating and re-contacting the spinning perforated basket. When this occurs, the result is foam. Eventually, the amount of foam is amplified to the point of suds-locking the washing machine, a condition where the drain pump is no longer able to evacute the suds. During a suds-locking condition, suds may develop to the point where they exert an excessive load on the motor used to drive the spinning basket. To prevent this problem, it is desirable direct the evacuated wash water towards the base of the tub as quickly as possible. This would minimize water build up and any resultant foaming conditions.

[0007] Prior attempts at directing water's movement in the region between the outer tub and the perforated basket have included U.S. Pat. No. 5,671,617 which issued to Park et al. on Sep. 30, 1997. However, the Park patent uses a series of collars on one of the two interior perforated baskets to recycle water onto the top of the clothes during the wash cycle. Wash water is extracted in a conventional manner and no effort is made to direct the flow of evacuated water during the spin cycle.

[0008] A general objective of the present invention is to provide a washing machine that solves the problems found with the prior art.

[0009] A further objective of the present invention is to provide a washing machine that can affect the flow of water between the perforated basket and the outer tub.

[0010] Another objective of the present invention is to provide a washing machine that efficiently collects wash water during the spin cycle.

[0011] A still further objective of the present invention is to provide a washing machine that minimizes excessive sudsing in the region between the perforated basket and the outer tub.

BRIEF SUMMARY OF THE INVENTION

[0012] The foregoing objects may be achieved by the washing machine of the present invention. The present invention generally comprises a cabinet in which a perforated wash basket is mounted in a conventional manner. An agitator, drive motor and drive mechanism are mounted within the cabinet, as is well known, to operate the washing machine.

[0013] Between the perforated wash basket or interior chamber and the cabinet is a tub or outer chamber to collect and contain wash water. The tub has a side wall that includes one or more grooves to direct wash water downward toward a collection area during the spin cycle. Preferably, the groove includes an under-cut portion that prevents collected water from flowing out of the groove.

[0014] During the spin cycle, the motor operates to turn the perforated basket at a high speed. This causes wash water to be extracted from the clothes or articles in the perforated basket. The water flows through the perforations in the basket and out to the tub wall. Because the basket and clothes are spinning at a high rate, the water flows out of the perforated basket and continues to flow in the direction of the spinning basket. When the water contacts the grooves, the flow is redirected to evacuate the water in a more efficient manner thereby minimizing sudsing conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a cross-sectional view of a washing machine.

[0016]FIG. 2 is a sectional side-view of the interior washing apparatus including a tub of the present invention.

[0017]FIG. 3 is a sectional side-view of the interior washing apparatus including an alternative tub of the present invention.

[0018]FIG. 4 is a top sectional view taken generally along line 2-2 of FIG. 2.

[0019]FIG. 4A is an enlarged view of section A of FIG. 4 shown during operational conditions.

DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be described as it applies to its preferred embodiment. It is not intended that the present invention be limited to the described embodiment. It is intended that the invention cover all modifications and alternatives which may be included within the spirit and scope of the invention.

[0021] Now, referring to the drawings, FIG. 1 illustrates a cross section of a typical washing machine 10. The washing machine 10 includes a cabinet 12, a control panel 14, an access opening 16 and an associated door (not shown). A reversible drive mo tor 18 of conventional construction is mounted within the lower portion of the cabinet 12.

[0022] The motor 18 is preferably secured to a web 20 by one or more brackets 22. The motor output shaft 24 extends upwardly through a clutch 26 shown schematically in FIGS. 2 & 4. The clutch 26 is adapted to respond to the rotational direction of the shaft 24 to engage/disengage the hub 28 that is connected to a spherically shaped basket 30.

[0023] The basket 30 includes a plurality of perforations 32 in the spherical shaped walls for permitting fluid communication between the interior of the basket 30 and the tub 34. Thus, as fluid is introduced into the basket 30, the fluid flows through perforations 32 and enters tub 34 also. As is further depicted in FIG. 1, the web 20, drive motor 18 and the washing assembly are shown suspended from the inside of cabinet 12 by a conventional hung strut suspension system 36 which is of known construction and does not comprise part of the instant invention.

[0024] The washing assembly also includes one or more agitators 38 that operate in a manner as described in U.S. Pat. No. 6,220,063 to Wunderlich on Apr. 24, 2001. During the washing action, rotation of shaft 24 causes clutch 26 to simultaneously disengage hub 28 from shaft 24 and secure hub 28 against rotation. This enables shaft 24 to rotate freely within hub 28 to drive the agitators 38 while also preventing rotation of basket 30.

[0025] After the washing cycle has completed, the motor 18 is reversed, causing a reverse rotation of shaft 24. This reverse rotation of shaft 24 causes clutch 26 to couple the shaft 24 to the hub 28, while simultaneously allowing free rotation of hub 28, thereby causing the basket 30 to rotate for the spin cycle. During the spin cycle, the washing fluid passes outwardly through perforations 32 and into the tub 34 due to centrifugal force.

[0026]FIG. 2 shows the tub 34 of the present invention. The tub 34 includes a lower portion 40 and an upper portion 42. The inner wall of the upper portion 42 includes one or more grooves 44 as is shown in FIG. 4. As shown in FIG. 2, the groove 44 preferably runs along the entire upper portion of the tub 34, but may be of any length, width or depth as desired.

[0027] The groove 44 also preferably runs in a generally vertical direction, though it may be angled or even spiral around the inside wall of the tub 34 as shown in FIG. 3. Preferably, the tub 34 is made of a plastic material and formed through well known injection molding techniques. Alternatively, the tub 34 may be formed of stainless steel, coated metal, or any other durable material using well-understood techniques.

[0028] Using a mold, the groove 44 is easily formed into a variety of shapes and sizes. The groove 44 preferably includes a front entry portion 46 and an under-cut channel portion 48. The under-cut channel portion 48 preferably extends away from the front entry portion 46 in the same direction as the direction of spin of the perforated basket 30 during the spin cycle. In order to prevent undue oscillation during the spin cycle, a balancing arrangement of grooves should be used. This means the grooves should be equally spaced along the wall of the upper portion 42 of the tub 34.

[0029] As is shown in FIG. 4A, during the spin cycle the basket 30 spins to expell water from the interior of the basket 30, through the perforations 32, and into the region between the basket 30 and the tub 34. Because the basket 30 is spinning at a high rate of speed, the water will generally continue to flow in the direction of the spinning basket 30. As the water flows along the wall of the tub 34, it eventually comes into contact with the groove 44. The outwardly flowing water enters the groove 44 through the front entry portion 46. When the water contacts the under-cut channel portion 48, the outward rotational flow of the water is redirected into a downward flow as illustrated in FIGS. 2 and 3. Eventually, the water flows into the lower tub portion 40 which terminates in a bottom wall 50 where it is collected and removed through a discharge port (not shown).

[0030] By redirecting the flow of water, the under-cut portion 48 reduces the amount of water spinning around the inside wall of the tub 34. This helps to minimize sudsing conditions thereby preventing suds lock from occurring.

[0031] While the invention is shown in a washer with a spherical tub and a vertical spin axis, it is envisioned that it could be applied to a conventional vertical axis washer with a cylindrical tub, a conventional drum-style horizontal axis washer, or a washer with any spin-axis angle therebetween.

[0032] A general description of the present invention as well as a preferred embodiment of the present invention has been set forth above. Those skilled in the art to which the present invention pertains will recognize and be able to practice additional variations in the methods and systems described which fall within the teachings of this invention. Accordingly, all such modifications and additions are deemed to be within the scope of the invention which is to be limited only by the claims appended hereto. 

What is claimed is:
 1. A washing machine having an inner chamber which rotates about an axis of rotation and an outer chamber, the outer chamber comprising: an upper portion having a groove formed therein for directing water downwardly towards a discharge port and traversing the side wall; and a lower portion connected to the upper portion.
 2. The outer chamber of claim 1 wherein the groove includes an undercut portion.
 3. The outer chamber of claim 1 wherein the groove traverses the entire length of the upper portion.
 4. The outer chamber of claim 1 wherein the groove is vertically disposed.
 5. The outer chamber of claim 1 wherein the groove is angled with respect to the axis of rotation.
 6. The outer chamber of claim 1 wherein the groove traverses in a direction parallel to the axis of rotation.
 7. A washing machine that minimizes sudsing during the spin cycle, the washing machine comprising: a cabinet; a motor secured within the cabinet; a tub mounted within the cabinet; a perforated basket mounted within the tub and operatively connected to the motor; a groove formed in the tub for directing fluid spun out of the perforated basket in a downward direction; and a drain within the cabinet to direct fluid away from the tub.
 8. The washing machine of claim 7 wherein the groove includes an undercut portion.
 9. The washing machine of claim 7 wherein the groove is disposed at an angle with respect to the axis of rotation.
 10. The washing machine of claim 7 wherein the groove is disposed vertically.
 11. The washing machine of claim 7 wherein a plurality of equally spaced grooves are used.
 12. The washing machine of claim 7 wherein the tub includes an upper portion and a lower portion and the groove is formed in the upper portion.
 13. A method of minimizing sudsing in a washing machine during the rinse cycle, the method comprising: forming a groove in a tub of a washing machine, the groove having an undercut portion; rotating a wash basket inside the tub to remove waste wash water from the basket; routing waste wash water down the groove to prevent excess sudsing; and removing the waste wash water from the tub.
 14. The method of minimizing sudsing of claim 13 wherein the a plurality of grooves are formed and equally spaced along the wall of the tub.
 15. The method of minimizing sudsing of claim 13 wherein the groove is formed with a shallow end and a deep end and wherein the basket is rotated in the direction going from the shallow end to the deep end of the groove. 